Bookbinding-machine



W. B. STORY.

BOOKBINDING MACHINE. APPLICATION man 1A|\1.2o,x919.v

Patented May 31, 1921.

3 SHEETS-SHEET 1.

iofl nullllel Patented May 319 1921,

s sHEETsf-SHIEET l2..l

w. B'. STORY., BoQKmnlNG MACHINE.

APPLICATION FILED IAN-20,1919.

w. B. STORY.

BooKlNmNG MAcHlNE.

' v APPLICATION FILED ]AN. 20, 1919. 1,380,265, Patented. May 31, 1921.

' 3 SHEETS-SHEET 3.

UNITED STATES PATENT OFFICE.

WARD B. STORY, OF BROOKLYN, NEW YORK, ASSIGNOR T0 T. W. & C. B. SHERIDAN *y COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

BooKBmDING-MACHTNE.

Specification of Letters Patent. Patgntgd May 31 1921.

Application ledvJVanuary 20, 1919. Serial No. 272,122.

To all 'whom t may concern v.Be it known'that l/VARD B. STORY, a citizen otthe United States ot' America, and a resident ot Brooklyn, New York, have invented a new and useful improvement in Bookbinding-Machines, which invention is fully set forth in the 'following specification.

The present invention is an improvement in book-binding machines ofthe type shown in Bredenberg Patents Nos. 1,248,252 and Reissue 14,485, wherein groups of signatures, assembled in a gathering machine, are subsequently introduced into a train ot traveling clamps in i which they arel held with their lower rear edges exposed to the action of the binding instrumentalities, after passing which the books are discharged into a suitable delivery.

lt sometimes happens in gathering or bookassembling machines, wherein signatures are simultaneously ted from a plurality ot sheet or signature sources to a common conveyer, that a signature will tail to be 'ted to the conveyer at some particular sheet or signature source (or a detective signature fed), whereupon the rsignature group that is short a signature, or into which the imperfect signature has entered,`will be defective.

It has been. heretofore proposed to separate such defective signature groups from the perfect books by providing mechanism, controlled by detecting devices associated with each sheet or signature source, to r separating the deteetiife books from the pertect books at the delivery. Machines of this type areL illustrated in patents to Dexter No. 653,196, King No. 1,041,806, and Juengst No. 1,126,026, in each of which is provided a main conveyer to which sheets or signatures are ted from a plurality et sources ot' sheet or signature supply, and a detecting mechanism tor each sheet or signature source. 1n the Dexter and Juengst machines, a procession of stops are moved with the said conveyer, said stops being operated by said detecting means, to separate the detective trom the perfect books,vand to distribute'said books into two deliveries or piles.

While such a separating or switching construction is desirable` it has been found that, in a machine employing an endless train of talities.

clamps which carry the groups of signatures past the binding instrumcntahties (such as illustrated in Bredenberg Patent No. 1,248,252), this switching or separating of the good from the detective books may be `profitably eliminated, the detective groups of signatures being ted to the train of traveling clamps with the perfect books,

introduced into the appropriate clamps in clamp in the endless chain, with the resultv that the lower normally-projecting edge or back ot the book is raised above the line of operation of the trimming, roughening, gluing, covering, cover-breaking and the other devices constituting the binding instrumen- The detective group of unbound signatures is discharged into a common delivery with the perfect books.

By means of such a construction for preventing the operation of the binding instrumentalities on the detective groups ot signatures, the machine is greatly simpliied, as the necessity for switching or separating devices, and the complicated means for operating the same (such as shown in the Dexter,

King, and Juengst patents referred to), is

removed. v

Any suitable or desired detecting mechanism may be employed for preventing the operation of the binding instrumentaiities on the defective group, either ot the teeler variety,'as shown in the 4Dexter or King patents,'or of the calipering variety as disclosed in the Juengst Patents 1,126,026 and 761,496. Preferably plurality of stops are mounted 0n a rotating carrier, one of said stops or members being set or rendered operative upon the absence of a signature, or the presence. of a defective signature, so that, at an appropriate time corresponding to the moment when the defective Group is being grasped vby its clamp, said stop or member so set operates, through suitable connections, to slightly7 elevate said defective group. The result is that theV clamp closes on the defective group which has been elevated so that its backedge is above the normal line of movement of that of the perfect books, whereupon the binding instrumentalities cannot act on the same.

The present device, so far as I am aware, is the first wherein groups of signatures are fed in a train of clamps past binding instrumentalities, with means, controlled by suitable detecting mechanism, for preventing the operation of the binding instrumentalities; and a single delivery7 into which the perfect and bound books, and the unbound defective signature groups, are discharged. Such a machine has certain obvious advantages which will be apparent to one skilled in the art.

Vhile the invention has been illustrated herein as embodied in a machine of the perfect binding7 type, e'. e. one in which the backs of the books are trimmed, roughened, glued, and cover applied, the invention may be also advantageously employed in association with covering machinesfemploying an endless train of clamps, but in which the signature-groups are stapled or wire-stitched before such groups are introduced inte the clamps. I have also shown and described herein means for tripping the cover-feed mechanism to prevent a cover being fed to the defective group.

The invention will be better understood by reference to the accompanying drawings, illustrating one embodiment of the inventive idea, and wherein- Figure 1 is a plan view of a book-binding and covering apparatus embodying the present invention;

Fig. 2 is a diagrammatic elevation, indicating a signature-gathering or assembling mechanism in association with the bookbinding and covering apparatus of Fig. 1 and showingthe application of the present invention Fig. S is a transverse section through one form of gathering machine, with various parts omitted, showing one form of detecting mechanism preferably employed;

Fig. 52L is a transverse section partly in elevation, of the structure shown in Fig. 4;

Fig. 4 is an enlarged detail on the line 4-4, Fig. 3, showing one of the carriers for the electromagnet and associated parts; and

Figs. 5 and 6 are details of the mechanism for elevating the leveling table.

Referring to the drawings, wherein like reference numerals indicate like parts, A indicates any suitable or usual form of gathering or assembling machine in which sheets or signatures are assembled in book form.

The groups of signatures are fed from Ythis gathering machine to a book-binding and covering machine B preferably of the type illustrated in Bredenbergy Patent No. 1,248,252, dated Nov. 27, 1917, wherein the signature groups are fed into an endless train of traveling clamps from an infeed trough C along which they are progressed while supported on their rear edges, as fully described in said patent. inasmuch as the signature groups at the end of the gathering machine are resting flatwise on table 10 (Fig. 3), suitable means are provided for receiving said groups in that position, turning the same and depositing them on their rear edges in the infeed trough C. Any suitable means D may be employed for this purpose but preferably there is employed the so-called rotary delivery7 or the twisted rail construction of Juengst Patent No. 846,928.

The gathering machine A is provided with a plurality of sources of sheet or signature supply, as hoppers 11, from which the lowermost sheets or signatures are simultaneously withdrawn and deposited on table 10, preferably slightly inclined, and along` which they are progressed in Jthe usual manner by pins 12 carried by endless conveyer 13. The withdrawing means are preferably of the well known swinging gripper `type comprising a pair of arms 14 each provided with a fixed jaw 15 and having a movable jaw 16 pivoted thereto at 7. Said movable jaw is moved toward said fixed jaw by a cam 18 operating through rod 19 in the well known manner described in Gritzendanner Patent No. 1,208,109. The wholegripper construction is rocked from shaft 20 in any suitable or usual manner.

Preferably the detecting mechanism for preventing the operation of the binding instrumentalities on defective signature groups is carried by one of said gripper arms 14. That detecting mechanism employs a bellcrank lever pivoted at 21 and having a short arm 22and a long arm 23. Said bell-crank lever is r cked on its pivot'by the engagement of a stud 16', carried by movable jaw 16, with a similar stud carried by the short arm 22. Pivoted on said vgripper arm 14 at 24, near the upper end of the long arm 23 of the bell-crank lever, is a detecting or contact finger 25 which, during the normal operation of the machine c when, signatures of a desired thickness are being withdrawn by the grippers) is moved by said bell-crank lever, through an intermediate member 26,

also pivoted at 24, to pass through the opening between two abutments 27 and 27. These abutments are mounted on an arm 28 carried by a sleeve encircling shaft 20,

and said arm 28 is adjustably connected to a second arm 29 preferably carried thereby.

When arm 28 is moved, arm 29 accordingly moves therewith; and, if no signature is seized by the gripper jaws, or if one that is too thin or too thick is seized, the finger 25 will engage one or the other of said abutments (the upper abutment in the event no signature is seized or one that is too thin, and the lower in case one that is too thick is seized), thus swinging the free end of arm 29 downwardly. In the end of arm 29 is mounted an insulated contact member 30 which is electrically.connected to a conductor 3l. This member 30 contacts with a spring-seated plunger 32, provided with a stem 33 which is encircled by a spring 3a, said plunger being carried by aninsulated fiber bushing mounted on the frame of the machine. rIhis plunger is electrically connected to a conductor 32', and when the aforesaid contact is made a circuit is closed through an electromagnet 36 (correspond-y `moment, and through suitable mechanism (hereinafter described) to elevate the defective group as it is seized by its clamp in the binding machine B, thus preventing the operation of the binding instrumentalities thereon. v

As heretofore stated, after the book leaves the gathering machine proper, it is turned from its iiatwise position until the signatures rest on their rear edges in the infeed trough or way C along which they are fed by a chain l1 provided with pushers 42 (Fig. l) that engage the books and progress them to the binding` machine.

rlhis binding machine preferably consists of an endless train of book clamps, each clam) consisting of an inner member 44 and a movable outer or presser-member 45. Each clamp membera is mounted to separate from and approach to its complementary clamp member 414i. for discharging, receiving and clamping the books; and a powerful spring device i6 is kprovided for each clamp to hold it closed lirmly upon the book until the clamp is opened, as by rail 4.7.

s each book reaches the top of the inclined trough C, under the influence of its pusher 42, it commences to enter cornerwise in the open boolwlamp and finally comes to a point above a leveling table 48 mounted on bracket i9 (Fig. The clamp guide rod (Fig. l) pushes the book forward with the clamp until the automatic closing of the same (due to the termination of the rail 4:7) causes the book to be firmly grasped between the clamp members-which occurs be for the book has passed beyond the position in which it is supported on the leveling table.

lf the signature group is defective, it is the object of the invention to prevent the 0peration thereon of the binding` instrumentalities indicated on Fig. 1. As is well understood in the art, and as fully described in Patent No. 1,248,252, these binding de vices operate on the lower exposed edges of the groups that project from the clamps. In the particular embodiment of the inventive idea here disclosed, the defective group is elevated as it rests on the leveling table 48 so that, when the clamp closes, the edges of the signatures of the defective group, which are normally operated on by the binding instrumentalities, will be out of range of the same; that is to say, the defective group will be clamped in such an elevated position that the binding means cannot perform their normal functions.

The elevation ol' the leveling table may be eifected in various ways, one'simple and preferred method being to utilize the set or operative trip 37, said trip preferably op erating when a defective group is resting on table 48 to elevate the latter just before the clamp is closed. i

The shaft 39 (F ig. 3a), on which is mounted wheel 38 that carries the trips 37, is supported in bearings in supports 5i and 52 which latter are mounted on the machine :iframe at 53. These supports carry a plurality of electromagnets 36, one for each source of signature supply.V For the sake of clearness, the electrical connections for only two of vthese electromagnets are shown, though it will be understood that each mag net is adapted to be energized by the closing of the circuit at its hopper. Alternate trips 37 are adapted to be moved laterally by the magnets on support 5l and the remainder by the magnets on support 52, though, if desired, a single large support carrying all the magnets might be utilized, in which event all the stops would be moved in the same direction. Any desired or suitable means for limiting the movement of the trips 37 when influenced by the magnets7 may be employed.

Shaft 39 is preferably driven from the mittcnt and preferably timed so that one of tl e 'trips 87 will be immediately opposite one of the electromagnets 3G at the time the Contact member 30 engages its correspond ing Contact member 32. Preferably there is employed the well known Geneva stop7 drive, one member 55 (Figs. 3a and 4) of which is mounted on shaft 56 and the other member 57 on shaft 58. Shaft 56 carries a bevel gear 59 that meshes with similar bevel gear 6() on drive shaft 54k, and shaft Both bers 55 and 57 of the Geneva drive.

oi' shafts 56 and 58 are mounted in suitable standards 6l. 5S has iixedly secured thereto a )imon 62 that meshesavith a wear i ,l D 63 fixedly secured to shart 39, the proportion beine nreilerabl such that one-oraiitoi1 b l. Y. 1 o of a turn o'l' pinion 62 Will rotate gear 6o an angular distance corresponding to the space between tivo oi the trips 3'! that project from the same side of Wheel 38.

The trip 37 which has been displaced laterally, or renoered ruiierative, elevates thc levelin(Y table at the appropriate time T3 .L l A through anv suitable moans but -ireieraol ca .i n l l there 1s provided a pair of levers (il and 65 (Fig. 5) pivoted, respectively, 66 and 67 to bracket A OaOes and suanorts the under side et table 2D n P L 48, but 1s not nredly comiected thereto. rThe other arm of said lever is preferably provided with a segment 66 that meshes with a similar segment 69 on one arm oi lever 65. The other ot lever 65 is secured to the under side oi table 46 at 70. Lever 64 is provided with a pair ci doivn- Wardl i aro ectinp lugs ll and F10'. 6

o Q t s the lugl l being adapted to be engaged by the trios 3'.' that are moved laterali from L 1 rone side of Wheel 38, and toe lug- ./2 by the trips on the other side ot saili'l Wheel. il] hen either of said lugs 7l or 'T2 is ,aged by a set trip 87, the longerV arm o lever 64: is elevated and. through the coii ctions vdeb 1 u scribed, also the longer arm o. lever (3othus eiilecting the necessar raising oi the table to elevate the defective signature group just prior to the closing of the clamp. A spring 73 may be employed, ii' desired. to assist in returning the parts to the position shovvn in full lines in Fig. 5.

Means are preferably provided whereby a trip 37 that has been rendered operative and Which has effec ed the elevation ot the tble 48 shall also operato the trip ot the ce 'feed to preventa cover boing led to the iective group oil signatures when it i the position at Which a cover is nero. aA I, applied. rilhis may be effected in any sui able manner, but preferably there is mmmy ed adjacent the periphey ci the Wheel orcarrier 38 a shaiet 74 (Figs. 3 and carried in lugs or brackets 75 projecting 'from the supports 5i and 52, on which the electromagnets are mounted. This sha'it 174-. has fixed thereon a pair ot trip arms Z6 and 7'?, one arranged on either side oi the rota-ting Wheel 38 and projecting into the path ot the set or operative trips 37. rlhe trip arm 76 Will be engaged by the trips that project from one side of the wheel 38 and the trip arm 7 7 b v the trips on the other side of said Wheel. When an operative trip 37 engages either arm 76 or 77, it rocks the same dovvn- Wardly and rotates shaft 74. Said shaft @ne arm'oiE lever (S enis operatively connected to the trip mechanism oit the cover feeder which may be, and preferably is, oi" the well-known Cross variety; an arm 78 (Fig. 3) secured to shaft 74: being connected to `one end of a linl; 79 (F ig. l), the other ond of said link being connected to an arm 8() that projects downwardly from the shaft orn the rover 'feeder on which the trip lever is mounted. The cover-feed mechanism tripped When the cover, which would otherwise be fed to the cover-applying poin l), is in position to be moved. yllhe time of tripping Would vary, for example, arcording to the distance of the cover supply from the cover applying point and the speed at which the cover is moved; but, assuming that the speed of movement 'of the rover and the speed oi' the train oi' endless clamps the same, the tripping would take place When the detective group was the saine distance from the cover-an 3l infy oint as the cover su 3 plyV is from that point. Y

The trips 37 are returned to their inoperative position by any suitable means, although there is preferably carried, by sinl ports 5l and 52, cam surfaces 8O and 81 (Fig. 3*) which are engaged by the set or operative trips ai'ter they have operated the arms and TZ, thus retin ing the trips to' their inoperative position.

any desired number oiA trips 37 may be mounted on the wheel 38, so long as the number is equal to or in excess of the number of hoppers or sources ott signature supply plus the number of spaces or stations between the point Where the signature groups are clamped at leveling plate i8 and the point Where the cover is applied. The number or stops that are needed will, as is Well understood, vary in different machines.

The operation of the device is as follows: Should a signature fail to be Withdrawn, for example, from a hopper or source of signature supply, the circuit will be closed at that point and one ot the electromagnets 36, corresponoing to the hopper Where the detect occurred, will be energized. T he trip opposite thereto-the Wheel 38 being preferably stationary at this moment-Will be displaced laterally, and thereafter said trip will raise the leveling` table 48, While the detective group is resting thereon, thus elevating said group just before the clamp closes thereon. Referring to Fig. l, let us assume that X indicates a detective group. The clamp is about to close, inasmuch as roller l5a is near the end of the track. The clefective group is elevated in the clamp at this time and the clamping will be eiiected as soon as the roller passes the end of the rail. Thereupon the defective group Will be carried past, but out of the range of operation of, the trimming, roughening, grooving, adhesive-applying, strip-attaching, cover-applying, and cover-breaking devices (when the invention is used with a machine of the v perfect binding7 type) and will be finally discharged, by the opening of the clamp, into the delivery with the good books, the unbound signatures of the defective group being thereafter picked out from among the good books by an operator.

rIhe continued rotation of wheel 38 will ultimately, and at the appropriate moment, cause the set trip 37 to rock shaft 74 and trip the cover-feed mechanism, thus preventing any cover being fed to the defective signature-group.

llVhile, for the purpose of clearness, one expression of the inventive idea has been herein described and illustrated in considerable detail, it is to be understood that the invention is not limited thereto, but that the inventive idea is susceptible of various electrical and mechanical expressions within the scope of the appended claims. Further, it is to be understoodthat, while the preferred use of the invention is in association with a machine of the perfect binding variety, it may also be used advantageously with simple covering machines wherein the groups of signatures are secured together, as by staplin, or wire-stitching, before the n book enters its clamp.

It is to be understood that by imperfect signature, as the term is hereinbefore used, is meant one that is too thick, too thin, or more than one; or a ltorn or reversed signature; and by defective signature-group is meant one into which a signature such as designated has been included, or a group that lacks one or more signatures.

IVhat is claimed is 1. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith and adapted to operate on the groups of signatures in lsaid clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the presence of animperfect signature as the groups are being assembled, and mechanism controlled by said means and operating on the group into which an imperfect signature enters to displace the same inits clamp and thus prevent the operationof the binding instrumentalities on said group.

2. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith and adapted to operate on the groups of signatures in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the absence of a signature as the groups are being assembled, and mechanism controlled by said means and operating on the defective group to displace the same in tsclamp and thus prevent the operation of the binding instrumentalities thereon.

8. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith and adapted to operate on the groups of signatures in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by said means and operating on the group into which an imperfect signature enters as said group is introduced into its clamp to prevent the operation of the binding instrumentalities on said group.

4. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith and adapted to operate on the groups of signatures in said clamps, means Vfor assembling signatures into groups and introducing them into saidfclamps, means for detecting the absence of a signature as the groups are being assembled, and mechanism controlled by said means and operating on the defective group as said group is introduced into the clamp to prevent the operation of the binding instrumentalities thereon.

5. In combination, an endless series of book-conveying' clamps, means for applying covers to the books in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by said means andA operating on the group into which the imperfect signature entered to displace the same in its clampand thus prevent the operation thereon of the coverapplying means.

6. In combination, an endless series of book-conveying clamps, means for applying covers to the books in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the absence of a signature as the groups are being assembled, and mechanism controlled by said means and operating on the defective group to displace the same in its clamp and thus prevent the operation thereon of the cover-applying means.

` 7. In combination, an endless series of book-conveying clamps, means for applying covers to the books in saidy clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by said means and operating on the group into which the imperfect signature entered as said group .is introduced ist@ its Clamp t0 Prevent the operation thereon of the cover-applying means.

8. In combination, an endless series of book-conveying clamps, means for applying covers to the books in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the absence of a signature as the groups are being assembled, and mechanism controlled by said means and operating on the defective group as said group is introduced into its clamp to prevent the operation thereonV of the cover-applying deans.

V9. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith and adapted to operate on the groups of signatures in said clamps, means for assembling signatures into groups and introducing' them into said clamps, means for detectingl the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by said means and operating on the group into which an imperfect signature enters to slightly elevate the same just before its clamp closes whereby the defective group is carried through its orbit at a greater elevation than the perfect books.

10. In combination, an endless series of book-conveying clamps, means for applying covers to the books in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by saidV means and operating on the group into Which'the imperfect signature entered to slightly elevate the same just before its clamp closes whereby the defective group is carried through its orbit at a greater elevation than the perfect books.

11. In combination, an endless series of book-conveying clamps, means for applying covers to the books in said clamps, means for assembling signatures into groups and introducing them into said clamps, means for detecting the absence of a signature as the groups are being assembled, and mechanism controlled by said means and operating on a defective group to slightly elevate the same just before its clamp closes, `whereby said defective group is carried through itsorbit at a greater elevation than the perfect books.

12. In combination, an vendless series of bookconveying clamps, means for applying covers to the books 1n said clamps, means for assembling signatures into groups and introducing them into said clamps,means for detecting the presence of an imperfect signature as the groups are being assembled, and mechanism controlled by said means and operating on the group into which the imperfect signature entered to slightly elevate rality of sources of sheet or signature supply and introducing said groups intosaid clamps, detecting means associated with each signature source and operating to detect imperfect signatures or the absence of a signature, and mechanism controlled by said detecting means and operating on a defective group to elevate the same just before its clamp closes.

14. In combination, a traveling clamp, means for assembling signatures into groups from a plurality'of sources of sheet or signature supply and introducing a group into said clamp, detecting means associated with each signature source and operating to detect imperfect signatures or the absence of signature, and means controlled by said detecting mechanism operating on a defective group to elevate the same just before said clamp closes.

15. In combination, a traveling clamp, a leveling table over which said clamp moves and on which signature-groups rest, means for assembling signatures into groups from a plurality of sources of sheet or signature supply and introducing a group into said clamp, detecting means associated with each signature source and operating to detect imperfect signatures orV the absence of a signature, and means controlled by said'detecting mechanism elevating said table when a defective group is resting thereony just before the clamp closes on said group.

15. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association there-With adapted to operate on the groups of signatures in said clamps, means for assembling signatures into groups and introducing them into said clamps, means forv detectingfthe presence of an imperfect signature as the groups are being assembled, a rotary carrier, a plurality of stops mounted thereon, connections whereby one of said stops is rendered operative by said detecting means, and mechanism controlled by said stop and operating on the group into which an imperfect signature enters to prevent the operation of the binding instrumentalities on said group.

'17. In combination, an endless series of book-conveying clamps, binding instrumentalities arranged in association therewith adapted tooperate on the'groups of signatures in said clamps, means for assembling signatures into groups and introducing themgroups are being assembled, a rotary carrier, a plurality of stops mounted thereon, electrical connections whereby one of said stops is rendered operative by said detecting means, and mechanism controlled by said stop and operating on the group into which an imperfect signature enters to prevent the operation of the binding instrumentalities on said group.

18. In combination, an endless series cf book-conveying clamps, binding instrumentalities arranged in association therewith including means for feeding covers adapted to operate on the groups of signatures in said clamps, means for assembling signatures into groups and introducing them inte said clamps, means for detecting the presence of an imperfect signature as the groups are being assembled, a rotary carrier, a plurality of stops mounted thereon, electrical connections whereby one of said stops is rendered operative by said detecting means, and mechanism controlled by said stop and operating on the group into which an imperfect signature enters to prevent the operation of the binding instrumentalities on said group, said stop also tripping the coverfeeding means to'prevent the feeding of a cover as said defective group passes.

19. In combination, an endless series of book-conveying clamps, a leveling table over which said clamps move and on which signature-groups rest, means for assembling signatures into groups from a plurality of sources of she-et or signature supply and introducing a group into one of said clamps, a rotary carrier, a plurality of stops carried thereby, detecting means associated with each signature source and operating to detect imperfect signatures or the absence of a signature, means controlled by said detecting means for rendering said stops operative, and means actuated by an operative stop for elevating said table when a defective group is resting thereon just beforethe clamp closes on said group.

20. In combination, an endless series of book-conveying clamps, a leveling table over which said clamps move and on which signature-groups rest, means for assembling signatures into groups from a plurality of sources of sheet or signature supply and introducing a group into one of said clamps, a rotary carrier, a plurality of stops carried thereby, detecting means associated -With each signature source and operating to detect imperfect signatures or the absence of a signature, electromagnetic means controlled by said detecting means for rendering said stops operative, and means actuated by an operative stop for elevating said table* When a defective group is resting thereon just before the clamp closes on said group. p

21. In combination, an endless series of book-conveying clamps, a leveling table over which said clamps moveand on which signature-groups rest, means for assembling signatures into groups from a plurality of sources of sheet or signature supply and introducing a group into one of said clamps, a rotary carrier, a plurality of stops carried thereby, detecting means associated with. each signature sourceand operating tov detect imperfect signatures or the absence of a signature, means controlled by said detecting means for rendering sait stops operative, cover-feeding meansxand means aetuated by an operative stop for elevating said table when a defective* group is resting thereon'just before the clamp closes on said group, said stop also tripping the coverfeeding means.

In testimony whereof l have signed this specification.

WARD B. STORY. 

